1. Technical Field
The present disclosure generally relates to well bore tools and in particular to apparatus and methods for downhole spectrometry.
2. Background Information
Oil and gas wells have been drilled at depths ranging from a few thousand feet to as deep as 5 miles. Wireline and drilling tools often incorporate various sensors, instruments and control devices in order to carry out any number of downhole operations. These operations may include formation testing, fluid analysis, and tool monitoring and control.
The environment in these wells present many challenges to maintain the tools used at depth due to vibration, harsh chemicals, and temperature. Temperature in downhole tool applications presents a unique problem to these tools. High downhole temperatures may reach as high as 200° C. (392° F.) or more, and sensitive electronic equipment may require cooling in order to operate properly in the downhole environment. An added problem is that space in the carrier assembly is usually limited to a few inches in diameter.
High resolution spectrometers, 1-2 nm bandpass for each optical channel for example, are typically completely located at a surface location with fluid samples being transported to the surface for analysis or they use optic fibers to carry light from the surface to a downhole sample. Some wireline tools use downhole spectrometers that analyze fluids in the downhole environment but generally at comparatively low spectral resolution of about 20-30 nm bandpass for each optical channel.